1. Field Of The Invention
The present invention relates to electrical connector assemblies and, more particularly, to totally hermaphroditic, environmentally sealed connectors, useful in instrumentation sensors, mining exploration, remote control applications, signal circuits, and communication links, with plug-to-plug and plug-to-receptacle mating.
2. Description Of The Prior Art
In geophysical mapping of terrain, frequently for oil, geophones are distributed over the terrain in a pattern, each of them being connected through an individual or "take-off" cable to a central or main line cable which may be a mile long and which leads to an instrument truck. Subterranean characteristics are determined by detonating an explosive charge and recording in the truck electrical signals produced by the geophones in response to earth vibrations induced by the explosive.
Generally, the main cable must be placed in short sections by a team of laborers and connected together under differing terrain and environmental circumstances as described in U.S. Pat. No. 3,725,845. The invention described in U.S. Pat. No. 3,725,845 was devised to overcome problems relating to laying the main or central cable, including but not limited to protection from environmental abuses such as rough handling by unskilled labor, inundation in water and general physical damage.
The problems solved by U.S. Pat. No. 3,725,845, however, did not overcome the problems relating to the individual or take-off cables leading from the main cable to one or more geophones. In particular, it is conventional to string take-off cables from the main cable in single or multiple patterns, such as take-off cables extending from a take-off cable. The take-off cables were secured to the main cable in a straight-forward, but environmentally unprotected manner. In many cases, a splice into two or more conductors in the main cable would afford a point of connection for the take-off cable, such as by alligator clips or male and female connectors. Such a connection is acceptable provided that moisture from inclement weather or watery terrain did not establish a short circuit between exposed alligator clips or corrode exposed connectors or that rough handling did not break the electrical connections.
Furthermore, just as with connections between main cable sections, as described in U.S. Pat. No. 3,725,845, locally available laborers usually lay the take-off cable and make the take-off connections. These laborers will in most instances be totally unskilled and unfamiliar with electrical connectors and with the method of their assembly. For example, they might not know the difference between a male and a female connector and, if they do know the difference, they might lay one take-off cable with a connector of one sex adjacent to another take-off cable whose connector is of the same sex and hence not mateable.
Therefore, it has been found desirable to eliminate this possible source of error by making the connectors hermaphroditic or identical at both ends of all take-off cable sections, as was the case with main cables in U.S. Pat. No. 3,725,845, so that it does not matter which end of the take-off cable is picked up to form the electrical connection.
After the explosive charge has been detonated and readings recorded, the geophones will be repositioned in a second pattern further along the direction in which mapping is to carried out. Consequently, additional or previously used sections of the main cable and the take-off cables must be successively connected to the newly positioned geophones. Since the exploration will typically progress in a long and substantially straight line, there will come a point where the main cable cannot be extended any further by adding additional sections. At this point the truck is driven ahead and a portion of the initially laid sections of the main cable with their take-off cables are disconnected, picked up and carried downstream from the last laid main cable sections where they are connected thereto so as to further extend the main cable in the direction in which the surveying operation is to progress and to lay down the same or different pattern of geophones on take-off cables connected to the main cable. Thus, it it may be seen that in the process of geophysical exploration, main cable sections with their take-off cables have to be connected and disconnected several times each day. Due to the large amount of handling to which the connectors are subject, they are susceptible to damage. This is aggravated by the fact that main and take-off cable sections may be left in the field, as well as on the truck, unconnected to other cable sections for extended periods of time so that, unless means are provided to protect their contacts, they are subject to corrosion, abrasion and other damage.
An additional problem is that some prior art connectors utilize male and female contacts in individual connectors. Although the female contacts are fully recessed in the connector and, therefore, are relatively well protected, the male contacts are exposed pins which are, at best, protected only by a single wall which surrounds them. Thus, they are protected only collectively rather than individually and, consequently, may be damaged or bent by a hard object being carelessly pulled across them.